Sighting apparatus for ordnance.



A. T. DAWSON 6: G. T. BUOKHAM.

SIGHTING APPARATUS FOR ORDNANGE.

APPLICATION FILED MAY 22, .1908.

Patented May 18, 1909.

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a f 072m f A. T. DAWSON 8; G. T. BUOKHAM. SIGHTINGAPPARATUS FORORDNANGB.

APILIOATION FILED MAY 22, 1908. 922,397, r Patented May 18, 1909.

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4- J I Q jaml/zil j gar JW w Q m h UNITED STATES TtATENT @FFTQE.

ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUCKHAM, OF WESTMINSTER, LONDON,ENGLAND, ASSIGNORS TO VICKERS SONS & MAXIM LIMITED, OF WESTMINSTER, ENG-LAND.

SIGHTING APPARATUS FOR ORDNANCE.

Specification 01. Letters Patent.

Patented May 18, 1909'.

Original application flled'fictober 23, 1907, Serial No. 398,717.Divided and this application filed. May 22, 1908.

Serial No. 434,230.

ments Relating to Sighting Apparatus for Ordnance, of which thefollowing is a specification.

This invention relates to sighting apparatus of the kind in whichthere-is a range dial and'a pointer so arranged that in impartingangular displacement of the dial relatively to the pointer the properelevation will be given to the sight to accord with a particular range.

We have already devised sighting appa z tus in which a graduated dial ismoved by hand gearing relatively to the pointer for setting the sightfor different ranges, means being provided whereby in the act of settingthe range dial relatively to the pointer, a correction Will beautomatically made to compensate for alterat ons 1n the muzzle velocityand changes in the temperature of the.

charges by changing the position of the pointer, so that in setting therange dial a greater or less angular movement will be imparted to. thedial in bringing a particular graduation or mark thereon intocoincidence with the pointer. These compensating means We term acalibrating device.

It is the chief object of our present invention to modify theconstruction of the said calibrating device.

Our present invention is particularly, although not; exclusively,intended for use with duplex sights of the well known crossconnectedkind.

We will describe our invention with reference to the accompanyingdrawings, in which Figures 1 to 3 illustrate the improved form ofcalibrating device combined with sighting apparatus in which thecorrection is effected by an angular movement imparted to thepointerthrough the calibrating device when the range dial receives itsmove.

ment from the hand gearing; Fig. 1 being a side elevation of. theapparatus; Fig. 2 a

horizontal section taken approximately on operated from a hand wheel Ain the usual manner, the said spindle A carrying the elevatingv inionfor changing the ele vation of the sight through the usual elevatingrack A3 B is the pointer.

The said calibrating device, comprisesthe cam or spiral groove a formedon or'in the range dial for actuating the roller (5 situated at the endof one arm d of the bell crank leverwhich is adapted to swing about anaxis or bearing-d on the dial casing. The other arm (i of the bell cranklever has the sliding or adjustable piece or block d, which is adaptedto be shifted and secured in any desired positionon this arm. This armbears a graduated scale for enabling the .block (Z to be set intheproper position thereon as required for the change in chargetemperature. The angular-1y adjustable pointer B is provided with an armorextension B, which by means of the link or rod (Z is connected withthe sliding block 6Z The said block is also provided with an adjustablemember or pointer (Z working adjacent to a graduated scale on the blockfor enabling the said adjustable member or pointer J to be set, by theactuation of a milled head (1, in the proper position for effecting thecorrections required for the change in muzzle velocity. The face of thearm d (Fig. 3) may be provided with temperature curves which arecarefully calculated to give the correct position for the sliding block(i When the range dial is actuated by the hand wheel A in theordinarymanner to bring the desired graduation thereon intocorrespondence with the pointer B, the cam or spiral groove a of thedial also imparts movement to the belLcrank lever (Z (l which in turnimparts angular movement to the pointer through the said connecting linkd and the arm or extension B on the pointer, the amplitude of theangular movement imparted to the pointer depending upon the position ofthe said sliding block (i on'the arm (1 .01 the bell crank lever and theextent of rotation imparted to the range dial by' the hand wheel A. Ifthe block is moved inward toward the pivot d of the bell crank lever, soas to bring the center of the contiguous end of the connecting h-nkclinto.

coincidence with the center of the pivot (lot the bell crank lever, themotion imparted to the bell-crank lever by the dial cam or spiral groovea vill not afi'ect the position of the pointer B. If however thesliding'block be moved outward or away from the pivot d of thebell-crank lever, the motion imparted to the latter by the dial cam orspiral groove will be transmitted to the pointer B through the said linkd to a greater or less extent according to the distance the slidingblock has been shifted from the pivot of the bellcrank lever. Thus theelevation given to the sight during the movement ofthe range dial inbringing the desired graduation into correspondence with the pointerWill be increased to an extent depending upon the position to which thepointer is set by the calibrating device. The requisite correctionfonthe fall in the muzzle velocity and the change in charge temperaturewill therefore be automatically effected. To. correct for muzzlevelocity and charge temperature the member d* is first set to the muzzlevelocity scale and then the sliding block (Z is moved along the arm duntil the arrow (Z on the member (1* touches the required temperaturecurve. Fig. 3 shows thecalibrating device set for a muzzle velocity or2675 feet per second and a charge temperature of 50 degrees Fahrenheit.

What we claim and desire to secure by Letters Patent of the UnitedStates is 1. In sighting apparatus for guns, the

combination with the range dial and its in den or pointer, of handactuated means tor setting the range dial with respect to the pointerand changing the elevation of the 'or member of said lever, and meanswhereby the position of the adjustable, piece affects the Xtent ofmovement imparted to the pointer during the hand setting operation.

2.. In sighting apparatus for guns, the

combination with the range dial and its indeX or pointer, of handactuated means for setting the range dial with respect to the pointerand changing the elevationbt the sights, a double armed or bell cranklever which one arm or member engages with a cam or spiral groove of therange dial an adjustable piece mounted on the other arm or member-of thesaid lever and connected with the pointer by means whereby the angularposition of the pointerwill be varied in accordance with theposition ofthe ad justable piece and the degree of motion imparted to the rangedial during the setting of the sights by the hand actuated means.

In testimony whereof we have hereunto set our hands in presence of twosubscribing witnesses this eighth dayoi' May 1908.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKllAEi. lVitnesses .llnnnr Kine,ARCHIE 'H. 'NICHULS.

